Storage Impact on Chlamydospore Germination of Arthrobotrys flagrans in Sodium Alginate Pellets

ABSTRACT This study aims to determine the shelf life of four batches of sodium alginate pellets containing the Arthrobotrys flagrans chlamydospores different storage conditions. Results showed that the germination rates of the chlamydospores in batches A and B increased in varying degrees at the indoor storage for 1 month but until 17 months of storage gradually declined to 0.52% and 0.48%, respectively. The germination rates in batches C and D gradually dropped to a minimum value at room temperature for 3–6 months but increased to the maximum value by 12 months and then again decreased to 1.26% and 2.22%, respectively, by 16 months. These pellets stored indoors were transferred to 4°C and −20°C storage. After storage for 2–5 months, the spore germination rates increased in different degrees. After the batch A and B pellets were stored at 4°C for 6, 12, and 30 months each, the chlamydospore germination rates increased to 10.76%, 11.87%, and 15.71%, respectively, for batch A and 29.63%, 8.34%, and 19.89%, respectively, for batch B. After the batch C and D pellet formulations were stored at −20°C for 1 year, the spore germination rates became twice as high as the initial values but close to their initial values at storage for 27 months. The data obtained in this study indicated that the shelf life of the pellets can be maintained for more than 2 years whether stored at 4°C or −20°C, between which the storage at −20°C was better.